I like the way you have related the modern day WT generations to those found in Matt chap 1. That clearly shows the nonsense idea of an overlapping generation.
Unfortunately with JWs, whatever the GB say over rides scripture. It is a very serious sin if a JW were to openly admit that something the GB says does not make sense. You must defend that belief with your life until the GB get new light, once this overlapping generation timeframe runs out. Then the new teaching will be so clear and obvious. But not until Tony's earthly course ends.